Apparatus for evaporating and distilling



A ril 9, 1946. E. P. WORTHEN ETAL 2, 9

- APPARATUS FOR EVAPORATING AND DISTILLING Filed March 22, 1945 10 Sheets-Sheet l April 1946; ,E. F;. WORTHEN ET AL 2,398,068

APPARATUS FOR EVAPORATING AND DISTIL IIING Filed March 22, 1945 10 Sheets-Sheet 2 and F 6MB ll/brmlz Fe 1 Sflarfioun il 1946- E; P. woRTHEN- TAL 2,398,068

APPARATUS FOR EVAPORATING AND DISITILLINQAZ Fild March 22, 1945 Y 16 S1egts-She et 4 li ljy'eet End.

E. P. WORTHEN ETAL APPARATUS FOR EVAPORATING AND DISTILLING Filed March 22, 19451 '16 Sheets-Sheet 5 A ril 9, 194

April 9, 1946. E. P. WORTHEN ET AL.

APPARATUS FOR EVAPORATING AND DISTILLING Filed March 22, 1945 1 0 Sheets-Sheet 6 April 9, 1946 E. P. WORTHEN ETAL APPARATUS FOR EVAPORATING AND DISTILLING Filed March 22, 1945 10 Sheets-Sheet 7 April 9, 194

E. P. WORTHEN ET AL APPARATUS FOR EVAPORATING AND DISTILLING Filed March 22, 1945 16 Sheets-Sheet 8 April 9, 194$. I E. P. WQQTHEN ET Ag 2,398,068

APPARATUS FOR EVAPORATING AND DISTILLING Filed March 22, 1945 10 Sheets-Sheet 10 F .1 Q 55 25! /E? j 210 H X; 2'44 2%! Zip/' E em]? [raw/w i r Sfiarbaur Patented Apr. 9, 1946 APPARATUS FOR EVAPORATING AND DISTILLIN Eugene lorter Worthen, Bralntree, and Fenner Smith, Barbour, Wollaston, Mass, assignors, by mesne assignments, to Buena Vista Iron Company, a corporation of New Jersey Application March 22, 1945, Serial No. 584,176

17 Claims.

This invention relates to an improved self-- contained apparatus for evaporating and distilling. It relates more especially to oil or gas fired distilling plants for use on board ships and in isolated localities where it is necessary to supply fresh or pure water demands from salt or contaminated water. It is especially useful where a supply of natural fresh water is not available and in addition thereto there is not readily available a source of steam heat suitable for initiating evaporation in a plural effect evaporating and distilling plant.

This invention relates more particularly to changes and improvements in the means for the production of pure water in evaporating and distilling apparatus that are disclosed in the copending patent application Serial No. 551,752, filed August 29, 1944, by Eugene Porter Worthen and Benjamin Fox.

The said co-pending application Serial No. 551,752 shows and discloses a small low pressure, single effect, oil or gas fired, evaporating and distilling plant more especially adapted for specific uses as are set forth therein. In the present case the effort has been to achieve additional economy and capacity for equivalent weight and space requirements of the evaporating and distilling plant by adapting the single effect design for plural effect evaporation and distillation. This effort has been rewarded by obtaining from the present design approximately twice the fresh water output for the same quantity of fuel burned with only a slight increase in size.

Therefore it is an especial object of our invention to provide a low pressure, plural efiect, oil or gas fired, evaporating and distilling plant that combines in a single compact unit three primary units-an oil or gas fired boiler, a first effect evaporator, and a second eiiect evaporator, and supplementary thereto the various essential elements required for the evaporating and distilling of salt or contaminated water.

The boiler is a special feature of our invention. Using submerged fire tubes it generates steam from fresh water within the boiler in a closed circuit requiring no. make-up water and no feed pump. The fire tubes submerged in the boiler water are supplied with the hot products of com bustion from an external oil or gas fired burner. The generated steam within the boiler rises and contacts the exterior surfaces of the first effect evaporator tubes exposed within the boiler whereby the boiler steam is condensed on the outside surfaces of said evaporator and transfers therefrom the heat of the hot products of combustion to the contaminated or salt water within the first effect evaporator tubes. By this arrangement the hot products of combustion are prevented from contacting the evaporator tubes and thus prevents the rapid formation of salt scale that would otherwise soon make the evaporating plant inoperative. A further feature of our boiler design is the use of inclined evaporator tubes, and in conjunction therewith having a removable cover plate over one end of said tubes whereby any salt scale that does accumulate within the said tubes may be readily removed by removing the said cover plate and turbining the tubes with any standard, turbine driven, rotary, tube cleansing elements.

Other objects of our invention is to so arrange the essential elements of our first effect evaporator unit and of our second effect evaporator unit, that the vapor generated by the boiling of the salt or contaminated water within the first efiect evaporator flows directly and sequentially through intercommunicating chambers of the first and second effect evaporators without the use of externalpiping, and that the said vapor is brought into contact. with and condenses on the exterior surfaces of the inclined evaporator tubes of the second effect evaporator. By this sequential and cooperating relationship of entirely internal intercommunicating chambers for the fiow of vapor from the first effect evaporator to the second effect evaporator a gain of economy and efilciency of operation is brought about, together with a saving in weight and space by reason of its compactness of design.

A further object of our invention is the provisionof means for, combining the generated vapors and their condensates of both the first effect and of the second effect in a single compartment prior to final condensation and removal as the finished product of the apparatus. It is known to those skilled in the art that the usual arrangement in a double effect water distilling plant is to have'the second effect evaporator tube nest drains (which are the condensed vapors generated in the first effect evaporator) discharge to an external flash chamber wherein their pressure and temperature are reduced to that of the second effect distilling condenser. The second effect distilling condenser also discharges its drains to the flash chamber and the combined product is withdrawn by a condensate pump and discharged through a separate external condensate cooler. In the process of reducing the second effect tube nest drains to the temperature and pressure of the distilling condenser, a portion of them (about 3 to 5%) vaporize or fiash." This fiash vapor passes through a vapor pipe from the top of the flash chamber to the distilling condenser where it is recondensed. In our improved arrangement a collecting chamber is provided which receives the purified vapors from the second effect separator (those which are generated in the second effect evaporator) and the drains from the second effect tube nest (which are the condensed vapors generated in the first effect evaporator), and then the combined vapors and drains, including any flash vapor released during the reduction in temperature and pressure of the drains, are passed to a combined distilling condenser and condensate cooler wherein the condensate is cooled considerably below the vapor temperature before it enters the combined condensate and vacuum air extraction pump. This results in a reduction of the number of separate heat exchangers required, and in having a single point of discharge of the product of the apparatus at the apparatus.

Further objects and advantages will be apparent from the following description wherein details of design and. operation will be given in full with reference to the accompanying drawings illustrating the preferred embodiment of our invention and wherein similar reference numerals designate similar parts throughout the several vlews.

Fig. 1 is a side elevation of our improved apparatus.

Fig. 2 is an elevation of the second effect end thereof.

Fig. 3is an opposite side elevation thereof.

Fig. 4 is an elevation of the first effect end thereof.

Fig. 5 is a section taken along the line 5-5 5-5-5 of Fig. 6 as viewed in the direction of the arrows.

Fig. 6 is a section taken along the line 6-6 of Fi 5 as viewed in the direction of the arrows.

Fig. 7 is a detail elevation of the second effect end with fire box cover removed.

Fig. 8 is a section taken along the line 88 of Fig. '1 as viewed in the direction of the arrows.

Fig. 9 is a section taken along the line 9-9 of Fig. 5 with the pedestal removed as viewed in the direction of the arrows.

Fig. 10 is a detail section taken along the line Ill-Ill of Fig. 4 as viewed in the direction of the arrows.

Fig. 11 is a detail section taken along the line I ||l of Fig. 4 as viewed in the direction of the arrows.

Fig. 12 is a detail section taken along the line |2-|2 of Fig. 4 as viewed in the direction of the arrows.

Fig. 13 is a detail section taken along the lin |3-|3|3 of Fig. 9 as viewed in the direction of the arrows.

Fig. 14 is a detail section taken along the line |4-|4|4-|4 of Fig. 1 as viewed in the direction of the arrows. 1

15 is a drawing representing in diagrammatic form the fiow system of the liquids to be distilled, of the heating fluids thereof, and of the condensate collecting means in an evaporating and distilling apparatus embodying our invention.

Referring now tc'the drawings, and more particularly to Figures 5 to 14, inclusive, the numeral designates the complete ensemble comprising a plurality of individual effects of a socalled multi-eifect evaporating and distilling apparatus. The drawings show a multi-eifect alent to the first and second effects herein shown.

The apparatus 20 comprises a casing preferably fabricated by welding together metal plates into a single unitary structure. This casing 25 acts-as the mounting structure for the elements of the boiler 2|, the first effect 22, the second effect 23, and those supported on the pedestal 24.

That part of the casing 25 comprising the mounting structure for the boiler 2|, the first effect 22, and the second effect 23 is, as may be noted particularly in Figures 6 and 9, substantially cylindrical except for an off-center segment along one side of the top half thereof, and is comprised of the wrapper plate 26, the evaporator top plate 21, the evaporator outer support plate 28, the feed heater outer wall plate 28, the first effect end plate 30, and the second effect end plate 3|.

That part of the casing 25 comprising the pedestal 24, as may be noted particularly in Figures 5, 6, and 9, is substantially arectangular box-like structure comprised of the longitudinal support plates 32, the end plates 33, the base plates 34, the inside corner brackets 35, and the vertical brace plates 36. The base plates 34 are provided with bolt-holes for foundation bolts (not shown).

The main substantially cylindrical portion of the casing 25 is divided internally into seven distinct compartments as follows: the boiler compartment 31, the first efiect evaporator vapor compartment 38, the vapor feed heater compartment 39, the second effect evaporator tube compartment 40, the second effect evaporator vapor compartment 4|, the second effect eva orator vapor discharge compartment 42, and the boiler water gauge and vent communicating duct 43.

The boiler compartment 31 extends full length and full width of the casing 25-occupying substantially the lower half of the cylindrical portion thereof. It is defined peripherally by the wrapper plate 25, the first effect half of the evaporator top plate 21, the bottom plate (53) of the second effect evaporator tube compartment 40, and the first effect half of the evaporator outer support plate 28, the evaporator inner support plate 44, the horizontal division wall plate 45, the end plates 3|! and 3|, the second effect evaporator tube compartment inner side wall (54), and I external expansion joint and tube sheet details to be hereinafter more fully described.

The first effect evaporator vapor compartment 38 extends half the length of the casing 25 on the circular side of the upper half thereof. It is defined peripherally by the wrapper plate 28, the horizontal division wall plate 45, the evaporator inner support plate 44, the first effect shut-off plate 45 (see Fig. 6), the vertical division wall plate 41, the first effect end plate 30, and the vertical transverse division wall plate 46 (see Fig. 5).

The vapor feed heater compartment 39 extends full length of the casing 25 on the segment side of the upper half thereof. (See Figs. 6, 9, and 13.) It is defined peripherally by the upper end of the wrapper plate 25 over the first eifect portion thereof, and by the vapor discharge comnally of the evaporator top plate 21, the second effect shut-off plate 58 (see Fig. 9) the vertical division wall plate 41, the end plates 36 and 3|, the comer 5| of the vertical transverse division wall plate 48 (see Fig. 9) and the inner end wall 52 of the vapor discharge compartment 42 (see Fig. 13) 7 The second effect evaporator tube compartment 46 lies over the boiler compartment 31 on the segment side of the second effect half thereof.

' It is defined peripherally by its half of the evaporator top plate 21 and of the evaporator outer support plate 28, the bottom plate 53, its half of the evaporator inner support plate 44, the second effect end wall 3|, the inner side wall 54 (see Fig. 13), and external expansion joint and tube sheet details to be hereinafter more fully described.

The second effect evaporator vapor compartment 4| extends half the length of the casing 25 on the circular side of the upper half thereof. It is defined peripherally by wrapper plate 26, the horizontal division wall plate 45, the evaporator inner support plate 44, the second effect shut-off plate 50, the vertica1 division wall plate 41, the second effect end plate 3|, and the vertical transverse division wall plate 48.

The second effect evaporator vapor discharge compartment 42 lies over the second effect half of the vapor feed heater compartment 39. It is defined peripherally by a portion of the upper end of the wrapper plate 26, the feed heater outer Wall plate 29, the bottom wall 49, the vertical division wall plate 41, the second effect end will 3|,and the inner end wall 52.

The boiler water gauge and vent communicating duct 43 is an auxiliary chamber of the boiler compartment 31 (see Fig. 6). It extends over the first effect half thereof and is separated therefrom by the evaporator top plate 21 but is communicated therewith by means of a plurality of orifices 55 in the intervening portion of the plate 21. The duct 43 is otherwise peripherally defined by the first effect shut-off plate 46, the vertical division wall plate 41, the first effect end plate 38, and the corner 5| of the transverse division wall plate 48. v

The boiler compartment 31 comprises therewithin a fire tube boiler 56 for generating steam from fresh water, ands, bank of first effect evaporating tubes 51 for evaporating saltwater on the inside of the tubes 51 by the condensation of the steam generated by the boiler 56 on the outside of the tubes 51.

The fire tube boiler 56 comprises the oil burner and blower unit 58, the front fire and smoke box 59, the fire tube furnace flue 68, the back fire and smoke box 6|, and the banks of fire tubessecond pass 62, third pass 63, and fourth pass 64. (See Figs. 3, 4, 5, 6 and 9.)

The oil burner and blower unit 58 is preferably a standard commercial pressure atomizing type of combined oil burner and motor driven blower for burning light diesel oil. However, arrangements can be made fOr burning almost any type of fuel oil or gas. The oil burner unit 58 is detachably mounted as by bolts (not shown) upon a support bracket (261) welded to the second effect end ofthe pedestal 24 and the outwardly extending front end of the fire tube furnace flue 66.

The front fire and smoke box 59 (see Figs. 3, 4, 5, 7, 8, 10, 11, and 12) forms theflre-tight compartment 65 surrounding the outer front end of the flue 68, and a smaller smoke-tight compartment 66 extending above the said compartment 65 in the right half thereof. The compartment 65 communicates the front ends of the second and third passes banks of flre tubes 62 and 63 with'each other. The compartment 66 communicates the front ends of the fourth pass bank of fire tubes 64 with the stack 15. The compartment 65 and 66 are peripherally defined by the wrapper plate 61 and division plate 68 welded to the first effect end plate 38 and to the front flange plate 69, and by the front end of the furnace flue 66 extending therethrough. The front flange plate 69 is welded to the end flange 10 of the furnace fiue 66. A large opening 1| is provided in the left half of the front-flange 66 opposite the front ends of the second pass fire tubes 62. Another large opening 12 is provided in the right half of the front flange plate 69 opposite the front ends of the third and fourth pass fire tubes 63 and 64. The opening 1| and 12 provide access for inspection and repair to the front ends of the respective fi're tubes, and are normally closed by cover p1ates'l3 and 14 removably attached to the front flange plate 69 as by cap screws (not shown). The compartment 66 is communicated with the atmosphere by meansof the stack 15 welded to the wrapper plate 61 and to the front flange plate 69, and is supported at its upper end by a bracket 16 attached to the first effect end plate 38. Flange walls 11 and 18 welded respectively to the cover plates 13 and 14 provide means for supporting conventional insulating material. Flange 19 welded to the wrapper plate 61 is also provided to provide support for conventional insulating material as is indicated in Fig. 3 at 88.

flue 60 with the back ends of the second pass bank of fire tubes 62; and a smoke-tight compartment 82 communicating the back ends of the third and fourth passes banks of fire tubes 63 and 64 with each other. The compartments 8| and 82 are formed by a wrapper plate 83 welded to the second effect end plate 3|. Welded to the outer edges of the wrapper plate 83 are the flanges 84 to serve as mounting mean for the flanged cover plate 85. The flanged cover plate 85 is removing means (such as bolts-not shown).

ably attached to the flanges 84 by suitable retain The interior of the compartment 8| formed by the wrapper plate .83 is lined with plastic refractory 86 and asbestos sheet 88 attached by means of anchor devices 81. The interior of the flanged cover plate is suitably lined with asbestos sheet material 88 and flre brick 69. A peephole 90 is provided through the cover plate 85 opposite the back end of the flue 60 and is equipped with a peep sight 9| through which combustion may be observed. The peep sight 9| may be removed and the opening 96 used for removing accumulated soot, etc. For further observation of smoking glasses.

and incomplete combustion an illuminated smoke indicator 82 is installed in the stack 18. Both the peep sight 8| and the smoke indicator 82 are served by a small air line broadly designated as pipe line connections 88 is piped from the burner fan discharge. This air line 83 when in operation keeps the observation glasses clean by. maintaining a current of air away from the observation The banks of fire tubes 82,88, and 84 are supported water-tight at their ends respectively in the first effect end plate 88 and the second effect end plate 3|. The bank of fire tubes 82 communicates the back fire compartment 8| with the front fire compartment 65. The bank of fire tubes 88 communicates the front fire compartment 85 with the back smoke compartment 82. The bank of fire tubes 84 communicates the back smoke compartment 82 with the front smoke compartment 65.

A water gauge 94 is shown in Figs. 3 and 4, and its casing connections are shown in Fig. 9. The lower connection 85 communicates the belowwater-line interior of the boiler compartment 31 with the lower end of the water gauge 94. The upper connection 96 passes-water-tight through the first effect evaporator vapor compartment 38 to communicate the boiler water gauge and vent communicating duct 43 with the upper end of the water gauge 94.

The first efiect bank of evaporating tubes 51 for evaporating salt or contaminated water on the inside thereof by the condensation of the steam generated by the boiler 56 on the outside thereof are supported water-tight at their lower outer ends in the first effect exterior evaporator tube sheet 91 and slope upwardly through the triangularly shaped pocket formed beneath the evaporator top plate 2'I'in the upper part of the first effect end of the boiler compartment 31, and are supported water-tight at their upper ends in the first efiect interior evaporator tube sheet 88. An opening 99 is provided in the first effect half of the evaporator inner support plate 44 through which the tubes 51 extend. The tube sheet 98 and the inner support plate 44 are suitably adapted for retaining devices such as studs (not shown) whereby the tube sheet 98 is removably attached to the inner support plate 44. .An opening I88 is provided in the first effect end of the evaporator outer support plate 28 through which the tubes 51 pass out of the boiler compartment 31. The lower ends of the tubes 51 together with their exterior tube sheet 81 are supported on the exterior face of the outer support plate 28 by means of the expansion joint II". The expansion joint I8I provides a water-tight seal for the boiler compartment 31 between the opening I88 and the tube sheet 81, and at the same time provides for expansion and contraction of the .tubes 51.- The expansion joint I8I comprises the flanged joint I82, the tube sheet clamp flange I83, the support plate clamp flange I84, the support plate studs and nuts I85, and the tube sheet bolts I88. Attached to the exterior face of the tube sheet 81 by means of the bolts I88 is the first effect feed water head I81 provided with the feed water inlet i removably attached as by cap screws (not shown) to the first effect end plate 88 (see Figs. 3 and 4) The cover plate III is provided with a sight glass H2, and a tapped hole II8 for a relief valve II4. Attached water-tight to the wrapper plate 28 exteriorly or the first effect evaporator vapor compartment 28 is the level control box II5 (see Figs. 3 and 6). The'level control box I I5 comprises the wrapper plate III, the top plate I", the bottom plate H8, and the flanged level control pipe connection III. The bottom plate H8 is provided with a clearance orifice I28 through which the pipe portion of the connection II8 projects upwardly into the interior of the level control box II! when assembled in place. The bottom plate H8 and the exterior flange of the connection II! is adapted for attachin elements such as cap screws (not shown) when assembled with the attaching flange of the discharge feed pipe to be hereinafter described. The height of the pipe II8 within the box III determines the level of the distilland within the first effect evaporator vapor compartment 88 when in operation-this by reason of vapor orifice I2I and water orifice I22 communicating the level control box II5 with the interior of the compartment 38. The first efl'ect evaporator vapor compartment 28 is communicated with the vapor feed heater compartment 38 by means of an opening I22 in the upper portion of the vertical division wall plate 41 extending substantially the full length of the evaporator vapor compartment 38. Placed over and commanding the opening I23 and detachably mounted on the wall plate." by suitable retaining devices (such as studs-not shown) is the vapor separator I24. The vapor separator H4 is preferably a standard Bethlehem vapor separator of the type and design shown and disclosed in the co-pending patentv application Serial No. 539,214, filed June 7, 1944, by Eugene Porter Worthen et a1. As the details of this separator are not elements of invention in the subject matter of this present application it will not be further described herein-it is only necessary for the purpose of the present application that the vapor separator I24 be an eiilcient device for the removal of moisture containing salt from the vapors generated from the distilland in the evaporator vapor compartment 38, and to return this moisture to the said distilland, and to pass on for condensation to and within the vapor feed heater compartment 88 a maximum fiow of the generated vapors so purified as to be within the permissible degree of salinity. The passageway I25 through the separator I24 is indicated conventionally by crossed dot-and-dash lines I25 in Figs. 5 and 13. In order to return the drainage from the separator to the body of the distilland below and beneath the surface thereof the separator I24 is provided with drainage pipe I26 and discharge cup I21.

The vapor feed heatercompartment 38 contains the vapor feed heater unit I28. The vapor feed heater I28 :is a unit removably attached by means of suitable fastening devices such as studs and nuts (not shown) to the outer face of the second effect plate 3| provided with an opening I29 through which the interior elements of the vapor feed heater unit I28 is assembled or withdrawn for inspection or repair. The vapor feed heater unit I28 comprises the outer tube sheet I38, which forms the attaching member and closing element for the opening I28, the outer conduit head I8I, the tube sheet support plate I32, the tube sheet support plate tie rods I33 with nuts I34, the inner tube sheet I35, the inner conduit head I36, and the four sets of tubes I31, I38, I39, and I-40, respectively.

The outer conduit head I3I (see Figs. 9 and 13) is preferably a casting removably attached by means of suitable fastening devices such as studs and nuts (not shown) to the outer tube sheet I30. The outer conduit head I3I is recessed and provided with two division walls I and I42 which form when the conduit head I3! is in place on the tube sheet I30 the chamberslower I43, intermediate I44, and upper I45, the feed water inlet connection I46, and the feed water outlet connection I41. The inner conduit head I36 is of similar construction having the single division wall I48 forming the chambers I49 and I50 (see Fig. 13).

The respective ends of the tubes I31, I38, I39, and I40 are supported water-tight in the outer tube sheet I38 and the inner tube sheet I35.

It may now be noted particularly in Fig. 13,-

that the chamber I43 is communicated with the chamber I49 by means of the tubes I31; the chamber I49 is communicated with the chamber I44 by means of the tubes I38; the chamber I44 is communicated with the chamber I50 by means of the tubes I39; and the chamber I50 is communicated with the chamber I45 by means of the tubes I40. i

For convenience in assembly and withdrawal of the vapor feed heater I28 the compartment 38 is provided with the bottom support guide II and the side guide. I52, which support the inner weight of the heater unit I28 by contacting the bottom and side edges of the tube sheet support plate I32, of the inner tube sheet I35, and of the inner conduit head I36, (See Figs. 9 and 13.) 1

The vapor feed heater compartment 39 (see Figs. 9 and 13) is communicated with the second efiect evaporator tube compartment 40 through the evaporator top plate 21 by means of the three orifices I53 for the discharge of vapor, and by means of the plurality of condensate drain ori-- fices I53"; both in the lowermost corners respectively of the second efiect half of the compartment 39 for the discharge of condensate-both vapor and condensate discharging to the second effect evaporator compartment 40.

The second efi'ect evaporator tube compartment 40 (see Figs. 9 and 13) contains the bank of evaporating tubes I54 for evaporating salt or contaminated water on the inside thereof by the condensation of the residual steam from the vapor feed heater compartment 33 on the outside thereof. The said tubes I54 are supported water-tight at their lower outer ends in the second effect exterior evaporator tube sheet I 55 and slope upwardly through the compartment 40 to be supported water-tight at their upper ends in the second efiect interior evaporator tube sheet I56. An opening I51 is provided in the second effect half of the evaporator inner support plate 44 through which the tubes I 54 extend. The tube sheet I56 and the inner support plate 44 are suitably adapted for retaining devicessuch as studs (not shown) whereby the tube sheet I56 is removably attached to the inner support plate 44. An opening I58 is provided in the second efi'ect end of the evaporator outer support plate 28 through which the tubes I54 pass out of the evaporator tube compartment 40. The lower ends of the tubes I54 together with their exterior tubesheet I55 are supported on the exterior face of vides a water-tight seal for the second effect evaporator tube compartment 40 between the opening I58 and the tube sheet I55, and at the same time provides for expansion and contraction of the tubes I54. The expansion joint I59 comprises the flanged joint I60, the tube sheet clamp'fiange I'6I the support plate clamp flange I62, the support plate studs and nuts I63, and the tube sheet bolts I64. Attached tothe exterior face of the tube sheet I55 by means oi the bolts I64 is the second effect i'eed water head I65 provided with the second efi'ect feed water inlet pipe connection I66. The compartment 40 is provided with the condensate drain connection I61 near the lower edge of the bottom plate 53. An

would normally pass through the horizontal di-' vision wall plate 45 of the second efiect evaporator vapor compartment 4| and the bottom plate 53 of the second effect evaporator tube compartment 40 into the second efi'ect with a resulting loss in emciency due to by-passing the first eilect. In order to minimize this loss as much as possible the insulating sheet I68 just described, and insulating sheet I88 hereinafter to be described have been provided. The insulating sheet I68 is provided, near a lower edge, with a single vapor vent hole I10. The compartment 40 is further provided with a tapped vent pipe connection I1I behind the outer support plate 28 in the second efiect end'plate 3| for a purpose to be further described hereinafter (see Figs. 2 and 9). The compartmentv 40 is provided with a tapped drain connection I12 in the lower edge of the tube sheet I55 for a pipe plug I13. (See Fi 9.

The second effect evaporator vapor compartment'4I (see Fig. 9) is provided with an opening I14 (see Figs. 2 and 6 for opening) in the second eifect end plate 3| whereby access may be had to the interior thereof for the purpose of assembly, inspection, and repair. The opening I14 is normallyclosed by means of the flat cover plate I15 removably attached as by cap screws (not shown) to the second eflect end plate 3| (see Fig. 2). The cover plate I15 is provided with a sight glass I16, a tapped hole I11 for a relief valve I18, and a tapped hole I19 for an air bleeder.valve I80. Attached water-tight to the wrapper plate 26 exteriorly of the second effect evaporator vapor compartment II is the level control box I8I (see Fig. 3). The detail construction and purpose of the level control box "II is similar to the level control box II 5 for the first efiect evaporator vapor compartment 38 and needs no further description than to designate its discharge brine pipe connection I82 to be further described hereinafter. The second effect evaporator vapor compartment 4| (see Fig. 9) is communicated with the second efi'ect vapor discharge compartment 42 by means of an opening I83 in the upper portion of the vertical division wall plate 41 extending substantially full length of the compartment 4|. Placed over and commanding the opening I83 and detachably mounted on the wall plate 41 by suitableretaining devices (such as studs-not shown) is the vapor separator I04. The vapor separator I04 is identical to the vapor separator I24 for the first effect and need not be further described than to designate the passageway I through the separator I04 and indicated by dot-and-dash lines I00 in Figs. and 13, and the drain pipe I00 and discharge cup I01. An essential element of the second effect evaporator vapor compartment H is the insulating sheet I00 welded to the bottom of the horizontal division wall plate 40. the sheet I00 for the second effect evaporator tube compartment 40 having the'dead air space I00, and vent hole I00, as has been described hereinbefore. I

The second effect vapor discharge compartment 42 (see Fig. 9) is provided with inlet pipe connection IOI in the upper part of the second effect end plate 0 I (See Fig. 2 for connection I0 I.) It is also provided with the outlet flange connection I02, and the inlet flanged connection I00 (see Fig. 1 for connections I02 and I00) in the outer wall plate 20 for the vapor discharge and condensate inlet respectively.

The boiler water gauge and vent communicating duct 40 is provided with the orifices 50 hereinbefore designated, the pipe connection I04 (see Fig. 9) for connection I04 in the first effect shutoif plate 40 for the upper gauge pipe connection 90, and the discharge vent pipe connection I95 in the first efi'ect end plate 00 (see Fig. 4). A companion inlet pipe connection I00 in the first eifect end plate 30 communicates with the vapor feed heater compartment 20.

We now come to the various units attached to the exterior of the casing 20 and forming cooperative connecting links and essential elements in the complete evaporating and distilling unit 20. Because of the conventional nature of these connecting links and essential elements in operation it will be convenient to describe these briefly along with a statement of the normal operation of the apparatus. It will be convenient to refer now more particularly to the Figures 1 to 4, inclusive, and, in order to more readily follow the flow systems of the liquids to be distilled, the heating means and fluids therefore, and the condensate collecting means it will also be convenient to refer to Figure 15 wherein the flow systems are shown diagrammatically. With respect to the latter drawing it is to be understood, that due to the limitations of a diagrammatic drawing, structural relationships must be further studied from the Figures 1 to 14, inclusive.

In preparation for use the boiler compartment 31 will be filled through the fllling'and drain pipe connection I01 (see Figs. 3 and 5) with pure water to a level somewhat above the top row of tube as will be indicated on the boiler water gauge 94. Since the boiler operates under a closed system, when in operation, the water is used over and over again and no make-up feed water is required. This results in the elimination of the usual boiler feed pump, controls, and piping, and also in the elimination of tube scaling due to impurities in the feed water.

In operation sea or other circulating water to be evaporated and distilled enters the apparatus 20 from the source of supply by way of the pipe I 00 (see Figs. 1 and 2) leading to the flanged pipe connection I90 of the combined condenser and condensate cooler 200.

The combined condenser and condensate cooler 200 (see Figs. 1, 2, and 14) is a conventional type of heat interchanger in which the feed water It serves the same purpose as does a,sos,oss

passes tortuously through a series of nests of tubes over and around which heated condensate and vapors pass on the exterior surfaces thereof, thus extracting heat from the condensate and vapors and adding it to the'feed water. As the specific details of this combined condenser and con- 1 densate cooler are not elements of invention in the subject matter of this present application it will not be described in complete detailit is only necessary for the purpose of the present application to describe its general operating features. The combined condenser and condensate cooler 200 (see Figures 1, 2, and 14) comprises preferably a cylindrical shell container 20I having the recessed front head 202 and the recessed rear head 203, and the nests of tubes 204, 200, 200, and 201. The nests of tubes are supported water-tight at their respective ends conventionally in the front tube sheet 200 and in the rear tube sheet 200 bolted respectively between the front head 202 and rear head 200 and their respective flanged ends of the container 20l. The front head 202 is provided with the feed water inlet flanged pipe connection I00, the circulating water discharge flanged pipe connection 2", the feed water discharge tapped pipe connection 2i I, the horizontal recess rib 2I2, and the vertical recess rib 2I0. By reason of the ribs 2I2 and M0 exchange medium over the adjacent tube sheet 200 and 2I0. The rear head 200 is provided with the angular rib 2I1 forming over the adjacent tube sheet 200 the chambers 2I0 and 2I0. The shell container 20I is also provided with a condensate and vapor flanged inlet connection 220, and level control box-22l. The level control box 22I is attached water-tight to the exterior of the shell container Ni and comprises the wrapper plate 222, the top plate 222, the bottom plate 224, the level control pipe 220, and the flanged outlet connection 220, It will now be readily understood that the feed water entering the combined condenser and condensate cooler 200 traverses sequentially the following circulating conduit elements therein: chamber 2. nest of tubes 204, chamber 2I0, nest of tubes 205, chamber 2I5, nest of tubes 200, chamber 2", nest of tubes 201, and chamber 2I0. In passing through the lower set of tubes 204 the circulating water serves as a condensate heat exchange medium-in passing through the upper series of tubes 20!, 200, and 201 the circulating water serves as a distilling condenser heat exchange medium. In leaving the chamber 2I0 the circulating water having served its purpose as a heat in its passage through the unit 200 is divided-a portion is diverted through the outlet connection 2i I to serve as feed water to be evaporated and distilled while the remainder is discharged to waste overboard through the outlet connection 2I0, valve 221, pipe line connections 220, and pipe 220. The water diverted through the outlet connection 2 continues onward by way of pipe line connections 230to the inlet pipe connection I40 in the outer conduit head III of the vapor feed heater unit I20. In next passing through the vapor feed heater unit I20 the circulating water traverses sequentially the following circulating conduit elements therein: chamber I40, tubes I31, chamber I40, tubes I00, chamber I44, tubes I30, chamber I00, tubes I40, chamber I40, and outlet pipe connection I41. In leaving the vapor feed heater unit I20 the circulating water has again served as a heat exchange mediumhas acted as a cooling agent for, and has absorbed heat from, the vapors within the vapor feed there is formed the chambers 2I4, 2I5,

aaoaooa The circulating water emerges from the vapor feed heater unit I28 from outlet pipe connection 41 and flows by way of pipe line connections 23 I, feed flow meter 232, pipe line connection 233, feed control valve 234, pipe connections 235, to discharge through the feed water inlet connection III! in the feed water head I01 of the first effect evaporating tubes 51. No feed pump is required since the pressure in the circulating water dis-- charge line is maintained at a greater pressure than that existing in the evaporator chamber 38 in communication with the tubes 51.

When the feed water enters the feed water head I01 it rises in the evaporator tubes 51 and overflows from their upper ends into the first efiect evaporator vapor compartment 38. The feed water then rises in the compartment 38 until it reaches the top of pipe portion of the connection H9 and the excess water then discharges there- .through as hereinafter described.

When the circulating water enters the evaporator tubes 51 and compartment 38 it becomes the distill-and for the apparatus 20. The system of level control and the supply of distilland used in the present apparatus 20 utilizes the basic principles of operation and the basic instrumentalities therefor shown and described in the co-pending patent application Serial No. 441,184, filed April 30, 1942, by Eugene Porter Worthen. The basic instrument-alities herein are the feed control valve 234 and the level control devices I I5 and I8'I hereinbefore described together with certain pipe connections herein next to be set forth. Briefly, this system of level control and supply of the distilland for the apparatus 20 comprises controlling the operating rate of flow of the distilling liquid to the first effect evaporating vapor compartment 38 of the apparatus 20 in constant substantial excess of that removed by evaporation within the apparatus as a whole, and further comprises, for each effect 22 and 23, having on their respective outlet conduits a level control device as hereinbefore described. The level control device in each case operates to receive the excess flow of liquid from its respective effect evaporating vapor compartment and to maintain the lquid level therein regardless of the operating rate of liquid flow thereto, and to pass the excess liquid on to the' next succeeding effect compartment, or in the case of the last effect compartment to discharge the final excess overboard.

The outlet level control pipe connection H9 of the first effect compartment 38 is communicated with the second efiect feed water inlet pipe connection I65 on the feed water head I55 of the second effect evaporating tubes I54 by means of the pipe line connections 236, loop seal pipe connections 231, with water gauge 238, and valve 239. The loop seal pipe connections 231 is provided in our preferred arrangement'of suificient depth to help maintain the desired pressure differential between the first effect and the second effect. In normal operation this is determined by having the preferred vacuum in the first effect vapor compartment'38 approximately 16" Hg, while that maintained in the second effect combined condenser and condensate cooler 200 is approximately 24" Hg. Furthermore we prefer to insert a feed feed water head I 55 it rises in the evaporator tubes I54 and overflows from their upper ends into the second effect evaporator vapor compartment 4I. Here, similarly as in compartment 38 for the first effect, the water rises until itreaches the top of the discharge brine pipe connection I82 and then the residual excess brine dischargeswater distribution baflle 240 with diffusion orifices MI in the inlet connection I66 of the feed water head I65 in order to more evenly distribute the water to all the tube ends therewithin.

When the feed water enters the second efiect therethrough to waste overboard by way of pipe line connections 242, pump 243, pipe line connections 244, check valve 245, pipe line connection 241, and pipe 229.

With the boiler compartment 31 filled, and feed water flowing throughthe apparatus 20 and discharging overboard, the fire tube boiler 2| is put into operation by starting the blower and burner unit 58. The oil burner flresinto the fire tube furnace flue 50." The hot gases emerging from the back end of the furnace flue 50 enter and transverse the fire box compartment 8i, and are here directed to enter and. traverse the bank of fire tubes 52 to the front end thereof, to enter and traverse the fire compartment 65, and are here directed to enter and traverse'the bank of fire tubes 53 to the rear end thereof, to enter and traverse the smoke compartment 82, and are here directed to enter and traverse the bank of fire tubes 64 to the front end thereof, to enter and traverse the smoke compartment 66, and thence to the atmosphere by way of the stack 15.

As a result of the circulation of the hot gases of combustion through the furnace and fire tubes as just described, the water within the boiler compartment 31 absorbs: the heat on the outside of the tubes and generates steam. The generated steam rises to the upper reaches of the boiler compartment 31 occupied by the sloping first effect evaporating tubes 51 and surrounding the exposed surfaces thereof, condenses thereon, and gives up its latent heat to the feed water inside the evaporating tubes 51, causing it to boil. The resultant mixture of water and vapor within the tubes 51 is discharged from the upper ends thereof into the first effect evaporator vapor compartment 38, while the water condensed on the outside of the tubes 51 falls back into the boiler compartment 26 to be regenerated over and over again.

When the apparatus is first put into use after a shut-down, a small diameter air bleeder valve I provided in the tapped hole I19 in cover plate I15 is opened and communicates the atmosphere with the second effect vapor compartment 4| for the purpose of preventing the air and condensate pump (260) from pulling a vacuum too quickly, thereby'causing violent flashing within the evaporating vapor chambers with a consequent carry-over of brine into the combined distilling condenser and condensate cooler 200.

It is also desirable occasionally, when the apparatus is in operation, to vent the boiler compartment to the first effect shell in order to prevent air from blanking off the boiler evaporator surface-this is provided for by the valve 248 and pipe line connections 249 communicating the discharge vent pipe connection I from the boiler water gauge and vent communicating duct 43 with the inlet vent pipe connection I96 of the vapor feed heater compartment 39-both connections being in the first effect end plate 30 (see Fig. 4).

The vapor discharged from the first effect evaporator tubes 51 rises to the upper confines of the first effect evaporator vapor compartment 38 and is drawn through the, separator I24 and opening I23 in the vertical division wall plate 41 into the vapor feed. heater compartment 38. In passing through the separator I24 the vapor gives up its entrained water which is returned through the drain pipe I28 and discharge cup I21 to the body of unevaporated water in the lower part of the first eflect evaporator vapor compartment 34.

The vapor entering the compartment it is drawn first downwards over the first effect ends of the vapor feed heater nests of tubes I41, I32,

I39, and I44, and then horizontally towards the second effect ends thereof, and thus circulating therethrough is partially condensed. The uncondensed vapor i next drawn downwards through the orifices I53 into the second eflect evaporator tube compartment 40, while the condensate drains thereto through the orifices I53.

The heated vapor and condensate discharged into the second effect evaporator tube compartment 4. surrounds the exposed surfaces oi the second efiect evaporator tubes II4 and condenses thereon giving up its latent heat to the feed water inside the tubes I54 causing it to boil. The resultant mixture of water and vapor within the tubes I54 is discharged from the upper ends thereof into the second efiect evaporator vapor compartment 4| while the water condensed on the outside of the tubes I54 falls to the bottom end of the compartment 44 and is discharged through the condensate drain connection I61.

The condensate emerges from the drain connection I61 and flows by means of the pipe connection 250, drain regulator 25l, pipe 252, valve 253, pipe line connections 254, and condensate inlet I92 in the outer wall plate 29, to discharge into the second effect evaporator vapor discharge compartment 42. Within the compartment 42, and opposite the inlet opening 01' the connection I43, a small bafile 2" is provided to prevent the incoming condensate from blowing back into the separator I84. The purpose of the drain regulator is merely to seal the second effect tube nest to prevent steam from blowing through the tube nest and discharging with the drains.

In order to maintain proper steam circulation near the lower end of the evaporator tubes I54 within the compartment 40 the tapped vent pipe connection "I is communicated with the vent inlet pipe connection HI, communicating with the compartment 42, by means of the line of pipe connections 2" and valve 241.

The vapor discharged from the second effect evaporator tubes I54 rises to the upper confines of the second eifect evaporator vapor compartment 4| and is drawn through the separator I84 and the opening ill in the vertical division wall plate 41 into the second effect evaporator vapor discharge compartment 42 where it joins the condensate discharged from the second effect evaporator'chamber 40 by way of the line of pipe connections 254.

The combined vapor and condensate is drawn from the compartment 42 by way of the outlet fiange connection I42, ,and fianged inlet connection 220 to the interior of the combined distillin condenser and condensate cooler 200 where the vapor is further condensed and the condensate is sub-cooled. The condensate rises in the condensate cooler portion to the height of the level control pipe 225. The level control pipe 225 is designed to discharge uncondensed vapor and.

gases together with condensate simultaneousl from the unit 204 and to mix them thoroughly in the discharge pipe line connection 254 communicating the flanged outlet connection 226 with the 2,ses,oes

inlet connection 244 of the air and condensate pump 280. The pump 2" discharges through the discharge connection 2" to condensate storage tanks (not shown).

It will be noted that the brine pump 242 and the air and condensate pump 244 are driven by a single motor 242 mounted in line with and between the pumps as a combined unit upon the second effect end of the pedestal 24 on a welded support bracket 2". The support bracket 243 comprises a mounting plate 244, standard plates 265, and angle brackets 244 welded to each other and to the pedestal 24 (see Figure 3) The mounting plate 264 is adapted for boltholes for mounting bolts (not shown). A similarly constructed support bracket 261 is provided on the first efiect end of the pedestal 24 for mounting the fan and motor unit 248 of the oil burner and blower unit 58 (see Figs. 3 and 4).

The apparatus 24 is provided with a number of operating accessories not hereinbefore set forth-they will now be noted briefly.

A salinity cell 243 is mounted on the condensate drain regulator 25L The salinity cell is used to give a continuous indication of the salinity of the condensate flowing through the drain regulator 25L The combined condenser and condensate cooler unit 200 is preferably attached to the casing 25 by means of paired plate brackets 210 welded conjointly to the evaporator top plate 21 and to the feed heater outer wall plate 24 of the casing 25, and to the cylindrical shell container 2M oi the unit 200 (see Figs. 1 and 2) The shaft bearing 21! of the brine pump 24;! is provided with a liquid seal by means of pipe line connections 212 communicating with the feed water inlet pipe III at the discharge connection 213 therein. The pipe line connections 212 include a strainer 214 and a valve 215.

Thermometers are provided as follows: Stack thermometer 216 on stack 15 (see Figs. 3 and 4). Vapor feed heater compartment 33 thermometer 211 (see Fig. 4). Feed water thermometer 214 in pipe line 234 (see Fig. 2). Boiler compartment 31 thermometer 219 (see Fig. 2).

Pressure gauges are provided as follows: Boiler compartment 31 pressure gauge 24! (see Fig. 4). Second effect evaporator vapor compartment 4! pressure gauge 24! (see Fig. 2).

Boiler safety valve 202 is provided for the boiler compartment 31 (see Fig. 4).

An oil burner master control 243 is mounted on the stack 15 (see Figs. 3 and 4) Although we have described and illustrated our invention in considerable detail, we do not wish to be limited to the exact and specific details thereof as shown and described, but may use such modifications in, substitution for, or equivalent thereof, as are embraced within the scope of our invention or as pointed out in the claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. 1n apparatus for evaporating and distilling liquids, a housing structure comprising a boiler adapted to contain a body of water operatively hermetically sealed therein and comprising a fiuid fuel burner and a stack outlet mounted exteriorly thereof, a plurality of fire tubes disposed below the level of said body of water and communicating said burner with said stack outlet, and means for firing said burner whereby heat and products of combustion may pass from said burner to said stack outlet in heat exchange relation with said body of water whereby vapor is generated therefrom, a first distilling effect comprising a first compartment, and a second distilling effect comprising a second compartment, a first condenser chamber connected to receive vapor from said first compartment, a second condenser chamber connected to receive vapor from said second compartment, conduit means for conducting liquid to be distilled successively in heat exchanging relation with vapor in the second condenser chamber, with vapor in the first condenser chamber, and with the vapor generated in said boiler enclosure whereby the said vapors are condensed and some of the liquid in said conduit is evaporated and the vapor thereof, is discharged along with the remaining liquid therein into said first compartment, a heater chamber connected to receive condensate and vapor from said first condenser chamber, conduit means for conducting excess liquid from said first compartment into heat exchanging relation with vapor in said heater chamber whereby the said vapor is condensed and some oi the liquid in said conduit is evaporated and the vapor thereof is discharged along with the remaining liquid therein into said second compartment, means for collecting for use condensates from said heater chamber and from said second condenser chamber, vapor exhausting means communicating with said second condenser chamber, and brine discharge means communicating with said second compartment.

2. In apparatus for evaporating and distilling liquids, a housing structure and a separate heat exchange unit mounted thereon, the housing structure comprising a boiler adapted to contain a bod of water operatively hermetically sealed therein and comprising a fluid fuel burner and a stack outlet mounted exteriorly thereof, a plurality of fire tubes disposed below the level of said body of water and communicating said burner with said stack outlet, and means for firing said burner whereby heat and products of combustion may pass from said burner to said stack outlet. in heat exchange relation with said body of water whereby vapor is generated therefrom, a first distilling eifect comprising a first compartment, and a second distilling efiect comprising a second compartment, a first condenser chamber connected to receive vapor from said first compartment, a vapor discharge chamber connected to receive vapor from said second compartment, conduit means for conducting liquid to be distilled successively in heat exchanging relation with vapor in said heat exchange unit, with vapor in the first condenser chamber, and with the vapor generated in said boiler enclosure whereby the said vapors are condensed and some of the liquid in said conduit is evaporated and the vapor thereof is discharged along with the remaining liquid therein into said first compartment, a heater chamber connected to receive condensate and vapor from said first condenser chamber, conduit means for conducting excess liquid from said first compartment into heat exchanging relation with vapor in said heater chamber whereby the said vapor is condensed and some of the liquid in said conduit is evaporated and the vapor thereof is discharged along with the remaining liquid therein into said second compartment, conduit means for conducting condensate and vapor from said vapor discharge chamber into said heat exchange unit, combined vapor and condensate exhausting means communicating with said heat exchange unit, and brine discharge means communicating with said second compartment.

3. In apparatus for evaporating and distilling liquids, a housing structure comprising a single container shell and external reenforcing and supporting elements therefor, the said shell being divided by longitudinal transverse walls into a lower boiler enclosure and an upper first and second effect evaporating and distilling enclosure, that portion of said walls separating said boiler enclosure from the second effect portion of the evaporating and distilling enclosure comprising insulating elements whereby direct heat exchange to said second effect is minimized thereby, the said boiler enclosure being adapted to contain a body of water operatively hermetically sealed therein and comprising a fiuid fuel burner and a stack outlet mounted exteriorly thereof, a plurality of fire tubes disposed below the level of said body of water and communicating said burner with said stack outlet, and means for firing said burner whereby heat and products of combustion may pass from said burner to said stack outlet in heat exchanging relation with said' body of water whereby vapor is generated therefrom. the said first and second effect evaporating and distilling enclosure comprising a first compartment, a second compartment, a first condenser chamber connected to receive vapor from said first compartment, a second condenser chamber connected to receive vapor from said second compartment, conduit means for conducting liquid to be distilled successively in heat exchanging relation with vapor in the second condenser chamber, with vapor in the first condenser chamber, and with the vapor generated in said boiler enclosure whereby the said vapors are condensed and some of the liquid in said conduit is evaporated and the vapor thereof is discharged along with the remaining liquid therein into said first compartment, a heater chamber connected to receive condensate and vapor from said first condenser chamber, conduit means for conducting excess liquid from said first compartment into heat exchanging relation with vapor in said heater chamber whereby the said vapor is condensed and some of the liquid in said conduit is evaporated and the vapor thereof is discharged along with the remaining liquid therein into said second compartment, means for collecting for use condensates from said heater chamber and from said second condenser chamber, vapor exhausting means communicating with said second c'on-' denser chamber, and brine discharge means communicating with said second compartment.

4. In apparatus for evaporating and distilling liquids, a housing structure comprising a single container shell and external reenforcing and supporting elements therefor, the said shell being divided by longitudinal transverse walls into a lower boiler enclosure and an upper first and second efiect evaporating and distilling enclosure, the said boiler enclosure being adapted to contain a body of water operatively hermetically sealed therein and comprising a fluid fuel burner and a stack outlet mounted exteriorly thereof, a plurality of fire tubes disposed below the level of said body of water and communicating said burner with said stack outlet, and means for firing said burner whereby heat and products of combustion may pass from said burner to said stack outlet in heat exchanging relation with said body of water whereb vapor is generated therefrom, the said first and secondeifect evaporatmg and distilling enclosure comprising a first compartment, a second compartment, a first condenser chamber connected to receive vapor from said first compartment, ,0. second condenser chamber connected to receive vapor from said second compartment, conduit means for conducting liquid to be distilled successively in heat exchanging relation with vapor in the second condenser chamber, with vapor in the first condenser chamber, and with the vapor generated in said boiler enclosure whereby the said vapors are condensed and some of the liquid in said conduit is evaporated therein, that portion of said conduit means engaging the vapor generated in said boiler enclosure being comprised of a plurality of intercommunicated transversely disposed water tubes sloping upwardlythrough the upper reaches of the first eflect end of said boiler enclosure to communicate with and to discharge their contents of vapor and liquid into said first compartment, a heater chamber connected to receive condensate and vapor from said first condenser chamber, conduit means for conducting excess liquid from said first compartment into heat exchanging relation with vapor in said heater chamber whereby the said vapor is condensed and some of the liquid in said conduit is evaporated therein, that portion of said last mentioned conduit means engaging the vapor in said heater chamber being comprised of a pluralit of intercommunicated transversely disposed water tubes sloping upwardly through the said heater chamber to communicate with and to discharge their contents of vapor and liquid into said second compartment, means for collecting for use condensates from said heater chamber and from said second condenser chamber, vapor exhaustin means communicating with said second condenser chamber, and brine discharge means communicating withsaid second compartment.

5. In apparatus for evaporating and distilling liquids, a housing structure and a separate heat exchange unit mounted thereon, the housing structure comprising a single container shell and external reenforcing and supporting elements therefor, the said shell being divided by longitudinal transverse walls into a lower boiler enclosure and an upper first and second eflect evaporating and distilling enclosure, that portion of said walls separating said boiler enclosure from the second eifect portion ofthe evaporating and distilling enclosure comprising insulating elements whereby direct heat exchange to said second effect is minimized thereby, the said boiler enclosure being adapted to contain a body of water operatively hermetically sealed therein and comprising a fluid fuel burner and a stack outlet mounted exteriorly thereof, a plurality of fire tubes disposed below the level of said body of water and communicating said burner with said stack outlet, and means for firing said burner whereby heat and products of combustion may pass from said burner to said stack outlet in heat exchanging relation with said body of water whereby vapor is generated therefrom, the said first and second efiect evaporating and distilling enclosure comprising a first compartment, a second compartment, a first condenser chamber connected to receive vapor from said first compartment, a vapor discharge chamber connected to receive vapor from said second compartment, conduit means for conducting liquid to be distilled successively in heat exchanging relation with vapor in said heat exchange unit, with vapor in the first condenser chamber, and with the aseaoea vapor generated in said boiler enclosure whereby the said vapors are condensed and some of the liquid in said conduit is evaporated and the vapor thereof is discharged along with the remaining liquid therein into said first compartment, a heater chamber connected to receive condensate and vapor from said first condenser chamber, conduit means for conducting excess liquid from said first compartment into heat exchanging relation with vapor in said heater chamber whereby the said vapor is condensed and some of the liquid in said conduit is evaporated and the vapor thereof is discharged along with the remaining liquid therein into said second compartment, conduit means for conducting condensate and vapor from said vapor discharge chamber into said heat exchange unit, combined vapor and condensate exhausting means communicating with said heat exchange unit, and brine discharge means communicating with said second compartment.

6. In'apparatus for evaporating and distilling liquids, a housing structure comprising a single container shell and external reenforcing and supporting elements therefor, the said shell being divided by longitudinal transverse walls into a lower boiler enclosure and an upper first and second effect evaporating and distilling enclosure, that portion of said walls separating said boiler enclosure from the second effect portion of the evaporating and distilling enclosure comprising insulating elements whereby direct heat exchange to said second effect is minimized thereby, the said boiler enclosure being adapted to contain a body of water operatively hermetically sealed therein and comprising a fluid fuel burner and a stack outlet mounted exteriorly thereof, a pinrality of fire tubes disposed below the level of said body of water and communicating said burner with said stack outlet, and means for firing said burner whereby heat and products of combustion may pass from said burner to said stack outlet in heat exchanging relation with said body of water whereby vapor is generated therefrom, the saidfirst and second effect evaporating and distilling enclosure comprising a first compartment, a second compartment, a first condenser chamber connected to receive vapor from said first compartment, a second condenser chamber connected to receive vapor from said second compartment, conduit means for conducting liquid to be distilled successively in heat exchanging relation with vapor in the second condenser chamber, with vapor in the first condenser chamber, and with the vapor generated in said boiler enclosure whereby the said vapors are condensed and some of the liquid in said conduit is evaporated therein, that portion of said conduit means engaging the vapor generated in said boiler enclosure being comprised of a plurality of inter-communicated transversely disposed water tubes sloping upwardly through the upper reaches of the first effect end of said boiler enclosure to communicate with and to discharge their contents of vapor and liquid into said first compartment, a heater chamber connected to receive condensate and vapor from said first condenser chamber, conduit means for conducting excess liquid from said first compartment into heat exchanging relation with vapor in said heater chamber whereby the said vapor is condensed and some of the liquid in said conduit is evaporated therein, that portion of said last mentioned conduit means engaging the vapor in said heater chamber being comprised of a 

